Mammary Paget disease is an uncommon malignancy of the breast that presents with ulceration or eczema of the nipple and is almost always associated with an underlying breast carcinoma. This disease is most commonly seen in the fifth and sixth decades of life and is almost always unilateral. The diagnosis of mammary Paget disease is generally based on clinical findings, confirmed by histopathologic examination. Mammographic and ultrasonographic findings may be nonspecific for malignancy, with 50% of cases showing negative findings. Magnetic resonance imaging can be used as a diagnostic tool to detect clinically occult cancer with nonspecific findings on mammogram and ultrasonogram. In this article, we are presenting a rare case of a young woman with biopsy-proven bilateral mammary Paget disease, for which bilateral modified radical mastectomy was done, followed by adjuvant chemotherapy and radiotherapy.